Gas turbine engine de-icing system

ABSTRACT

A de-icing system for a gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a forward assembly and a rear assembly adjacent to the forward assembly. One of the forward assembly and the rear assembly is rotatable relative to the other to generate an amount of air friction between said forward and rear assemblies. A method of de-icing a gas turbine engine is also disclosed.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/781,943, filed Oct. 2, 2015, which is a national stage entry ofInternational Application No. PCT/US14/32300, filed Mar. 31, 2014, whichclaims the benefit of U.S. Provisional Application No. 61/807,972, filedApr. 3, 2013.

BACKGROUND

This disclosure relates to a gas turbine engine, and more particularlyto a gas turbine engine de-icing system.

A gas turbine engine typically includes at least a fan section, acompressor section, a combustor section, and a turbine section. Airentering the compressor section is compressed and delivered into thecombustion section where it is mixed with fuel and ignited to generate ahigh-speed exhaust gas flow. The high-speed exhaust gas flow expandsthrough the turbine section to drive the compressor and the fan section.

During flight, ice can form on portions of the engine, such as on aspinner or a static nosecone of an upstream portion of a fan section.Ice build-up on the spinner, nosecone or other hardware can result inreduced engine efficiency and/or damage to downstream components causedby broken pieces of ice entering the core flow path of the engine. Anamount of heated bleed air or oil from a downstream compressor orturbine section of the engine is typically communicated to de-ice aportion of the gas turbine engine.

SUMMARY

A de-icing system for a gas turbine engine according to an exemplaryaspect of the present disclosure includes, among other things, a forwardassembly and a rear assembly adjacent to the forward assembly. At leastone of the forward assembly and the rear assembly is moveable relativeto the other of the forward assembly and the rear assembly to generatean amount of air friction between the forward and rear assemblies.

In a further non-limiting embodiment of the foregoing de-icing system,at least one of the forward assembly and the rear assembly is rotatablerelative to the other of the forward assembly and the rear assembly.

In a further non-limiting embodiment of either of the foregoing de-icingsystems, the forward assembly and the rear assembly are axially spacedapart.

In a further non-limiting embodiment of any of the foregoing de-icingsystems, the forward assembly and the rear assembly each includes atleast one paddle.

In a further non-limiting embodiment of any of the foregoing de-icingsystems, one of a spinner and a nosecone is in contact with the forwardassembly.

In a further non-limiting embodiment of any of the foregoing de-icingsystems, the one of the spinner and the nosecone defines an internalcavity, each of the forward assembly and the rear assembly at leastpartially located within the internal cavity.

In a further non-limiting embodiment of any of the foregoing de-icingsystems, the forward assembly includes a forward support structureextending from the one of the spinner and the nosecone, and the rearassembly includes a rear support structure extending from a fan hub.

In a further non-limiting embodiment of any of the foregoing de-icingsystems, a seal is configured to retain an amount of fluid within theinternal cavity.

In a further non-limiting embodiment of any of the foregoing de-icingsystems, an engagement mechanism is configured to move the rear assemblyin an axial direction between a de-icing position and an inoperableposition.

A gas turbine engine according to an exemplary aspect of the presentdisclosure includes, among other things, an exposed component definingan internal cavity and a de-icing system including a forward assemblyand a rear assembly each located within the internal cavity. At leastone of the forward assembly and the rear assembly is rotatable relativeto the other of the forward assembly and the rear assembly.

In a further non-limiting embodiment of the foregoing gas turbineengine, the forward assembly and the rear assembly are axially spacedapart.

In a further non-limiting embodiment of either the foregoing gas turbineengines, the forward assembly and the rear assembly each includes atleast one paddle.

In a further non-limiting embodiment of any of the foregoing gas turbineengines, the exposed component includes one of a spinner and a noseconein contact with the forward assembly.

In a further non-limiting embodiment of any of the foregoing gas turbineengines, a fan hub is mounted to the spinner.

In a further non-limiting embodiment of any of the foregoing gas turbineengines, an inlet guide vane assembly is mounted to the nosecone.

In a further non-limiting embodiment of any of the foregoing gas turbineengines, the forward assembly includes a forward support structureextending from the one of the spinner and the nosecone, and the rearassembly includes a rear support structure extending from a fan hub.

In a further non-limiting embodiment of any of the foregoing gas turbineengines, an engagement mechanism is configured to move the rear assemblyin the axial direction between a de-icing position and an inoperableposition.

A method of de-icing a gas turbine engine according to another exemplaryaspect of the present disclosure includes, among other things,mechanically generating an amount of heat within an internal cavity ofan exposed component and transferring the amount of heat from theinternal cavity to a surface of the exposed component.

In a further non-limiting embodiment of the foregoing method of de-icinga gas turbine engine, the step of mechanically generating the amount ofheat includes generating an amount of air friction within the internalcavity.

In a further non-limiting embodiment of either of the foregoing methodsof de-icing a gas turbine engine, the method includes the step ofrotating at least one of a forward assembly and a rear assembly relativeto the other of the forward assembly and the rear assembly tomechanically generate the amount of heat.

These and other features disclosed herein can be best understood fromthe following specification and drawings, the following of which is abrief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an example gas turbine engine.

FIG. 2 is a schematic view of a de-icing system.

FIG. 3 is a partial perspective view of the de-icing system of FIG. 2.

FIG. 4 is a schematic view of a second embodiment of the de-icingsystem.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates a gas turbine engine 20. The gasturbine engine 20 is disclosed herein as a two-spool turbofan thatgenerally incorporates a fan section 22, a compressor section 24, acombustor section 26 and a turbine section 28. Alternative engines mightinclude an augmentor section (not shown) among other systems orfeatures. The fan section 22 drives air along a bypass flow path B in abypass duct defined within a nacelle 15, while the compressor section 24drives air along a core flow path C for compression and communicationinto the combustor section 26 then expansion through the turbine section28. Although depicted as a two-spool turbofan gas turbine engine in thedisclosed non-limiting embodiment, it should be understood that theconcepts described herein are not limited to use with two-spoolturbofans as the teachings may be applied to other types of turbineengines including three-spool architectures.

The exemplary engine 20 generally includes a low speed spool 30 and ahigh speed spool 32 mounted for rotation about an engine centrallongitudinal axis A relative to an engine static structure 36 viaseveral bearing systems 38. It should be understood that various bearingsystems 38 at various locations may alternatively or additionally beprovided, and the location of bearing systems 38 may be varied asappropriate to the application.

The low speed spool 30 generally includes an inner shaft 40 thatinterconnects a fan 42, a low pressure compressor 44 and a low pressureturbine 46. The inner shaft 40 is connected to the fan 42 through aspeed change mechanism, which in exemplary gas turbine engine 20 isillustrated as a geared architecture 48 to drive the fan 42 at a lowerspeed than the low speed spool 30. The high speed spool 32 includes anouter shaft 50 that interconnects a high pressure compressor 52 and highpressure turbine 54. A combustor 56 is arranged in exemplary gas turbine20 between the high pressure compressor 52 and the high pressure turbine54. A mid-turbine frame 57 of the engine static structure 36 is arrangedgenerally between the high pressure turbine 54 and the low pressureturbine 46. The mid-turbine frame 57 further supports bearing systems 38in the turbine section 28. The inner shaft 40 and the outer shaft 50 areconcentric and rotate via bearing systems 38 about the engine centrallongitudinal axis A which is collinear with their longitudinal axes.

The core airflow is compressed by the low pressure compressor 44 thenthe high pressure compressor 52, mixed and burned with fuel in thecombustor 56, then expanded over the high pressure turbine 54 and lowpressure turbine 46. The mid-turbine frame 57 includes airfoils 59 whichare in the core airflow path C. The turbines 46, 54 rotationally drivethe respective low speed spool 30 and high speed spool 32 in response tothe expansion. It will be appreciated that each of the positions of thefan section 22, compressor section 24, combustor section 26, turbinesection 28, and fan drive gear system 50 may be varied. For example,gear system 50 may be located aft of combustor section 26 or even aft ofturbine section 28, and fan section 22 may be positioned forward or aftof the location of gear system 48.

FIG. 2 illustrates a portion 61 of a gas turbine engine 20 that caninclude a de-icing system 62. In this disclosure, like referencenumerals designate like elements where appropriate and referencenumerals with the addition of one-hundred or multiples thereof designatemodified elements that are understood to incorporate the same featuresand benefits of the corresponding original elements. In this embodiment,the portion 61 includes an exposed component such as a spinner 64.However, other parts of the gas turbine engine 20 may benefit from theseteachings. The spinner 64 is located partially within the fan section 22forward of the fan 42 to guide air along the bypass flow path B and thecore flow path C (see FIG. 1). The spinner 64 defines an internal cavity65 having a generally domed-shaped configuration and an interior surface71. Generally, an amount of fluid F is located in the internal cavity 65and may comprise an amount of air. In another embodiment, the fluid Fincludes an amount of oil. The fan 42 is mounted to a fan hub 66 at apair of flanges 73, 75 adjacent to each other. The fan hub 66 and thelow speed spool 30 are mechanically connected through the gearedarchitecture 48 (shown schematically in FIG. 1). The spinner 64 isattached to and rotates with the fan hub 66 about the longitudinal axis

A.

In one embodiment, the de-icing system 62 includes a rotating forwardassembly 74 adjacent to the spinner 64 and a counter-rotating rearassembly 76. The rear assembly 76 is axially spaced apart from theforward assembly 74 along the longitudinal axis A to define a gap Gtherebetween. The forward assembly 74 includes one or more forwardpaddles 78 and the rear assembly 76 includes one or more rear paddles79. Generally, each of the paddles 78, 79 extend radially about thelongitudinal axis A and are arranged adjacent to each other. Each of thepaddles 78, 79 may include a metallic, composite or other thermallyconductive material. The rear paddles 79 could also include a thermallynon-conductive material.

The forward and rear paddles 78, 79 are generally aerodynamicallyinefficient and may each include a generally planar configuration. Inanother embodiment, the forward and rear paddles 78, 79 may be concaveor convex. In yet another embodiment, the forward and rear paddles 78,79 may each include a plurality of protrusions, ridges, channels orother features to increase communication with the fluid F in theinternal cavity 65. Other shapes, sizes and orientations of the paddles78, 79 are also contemplated.

The forward paddles 78 may be supported by a forward support structure80 extending from a proximal end 81 of the spinner 64. Alternatively,the forward paddles 78 may be directly fastened to the spinner 64. Inanother embodiment, the forward paddles 78 may be welded, adhesivelybonded to or integrally formed with the spinner 64 to improve thermalconductivity therebetween.

The rear assembly 76 includes a rear support structure 82 that supportsthe rear paddles 79. The rear support structure 82 includes a firstsupport member 84 and a second support member 86. The first supportmember 84 extends along the longitudinal axis A between the rear paddles79 and the second support member 86. The second support member 86extends parallel to the longitudinal axis A between the first supportmember 84 and the fan hub 68. Generally, the second support member 86 isconnected to the inner shaft 40 or another rotating component of theengine 20. The rear assembly 76 may include a seal 92 (shownschematically), such as a knife edge seal, adjacent to the fan hub 68 toretain the fluid F in the internal cavity 65. Although a knife edge sealis described in this embodiment, other types of seal arrangements may beused such as a brush seal configuration, a labyrinth seal or anothertype of seal. By sealing the internal cavity 65, the pressure inside theinternal cavity 65 can be improved over an open cavity arrangement.However, an open cavity arrangement could also be incorporated. The seal92 may also be arranged in another location of the de-icing system 62,and more than one seal 92 may be included.

The rear support structure 82 may include a disengagement mechanism 90(shown schematically) disposed between the first and second supportmembers 84, 86. The disengagement mechanism 90 is configured to move thefirst support member 84 and the rear paddles 79 axially between ade-icing position and an inoperable position, thereby increasing thelength of the gap G. Generally, the paddles 78, 79 do not contact eachother when the rear paddles 79 are located in the de-icing position.When the rear paddles 79 are located in the de-icing position, the rearpaddles 79 oppose rotation of the forward paddles 78 in thecircumferential direction. Generally, the rear paddles 79 do not opposemovement of the forward paddles 78 when the rear paddles 79 are locatedin the inoperable position. The disengagement mechanism 90 may beaxisymmetric and may include one temperature-actuated component formedof a bimetal or a high coefficient of thermal expansion (CTE) material.However, other configurations to move the first support member 84 andthe rear paddles 79 are contemplated. The disengagement mechanism 90 mayalso be configured to minimize rotation of the rear paddles 79 and thefirst support member 84 about the longitudinal axis A.

During gas turbine engine operations, an amount of ice 93 can form on anexterior surface 95 of the spinner 64. The de-icing system 62 generatesan amount of heat H within the internal cavity 65 and transfers the heatH to the spinner 64. Referring to FIGS. 2 and 3, the forward paddles 78rotate about the longitudinal axis A in a direction 96, therebycirculating the fluid F within the internal cavity 65 generally in thedirection 96. The direction 96 may be either clockwise orcounter-clockwise with respect to the longitudinal axis A. The rearpaddles 79 are configured to counter-rotate about the longitudinal axisA in a direction 98 opposite to the direction 96. The rear paddles 79may extend axially toward the forward paddles 78 from the inoperableposition to the de-icing position thereby decreasing the length of thegap G. It should be understood that the rear paddles 79 may also beextended to the de-icing position before the forward paddles 78 begin torotate.

The rear paddles 79 do not rotate about the longitudinal axis A in thedirection 96 and therefore oppose the circulation of the fluid F in theinternal cavity 65. Therefore, the paddles 78, 79 mechanically generatean amount of air friction, commonly referred to as “windage.” The airfriction created between the paddles 78, 79 restricts the rotation ofthe forward paddles 78 in the direction 96, causing the forward paddles78 to generate an amount of heat H therein. The heat H is transferredfrom the forward paddles 78 to the interior surface 71 of the spinner 64by thermal conduction and by forced convection. As a result, thetemperature of an exterior surface 95 of the spinner 64 adjacent to theforward paddles 78 is increased, causing an amount of ice 93 accumulatedon the exterior surface 95 to melt. The rear paddles 79 may be retractedto the inoperable position when the aircraft is operating inabove-freezing conditions or other conditions, thereby preventing theforward paddles 78 from transferring an excessive amount of heat to thespinner 64.

FIG. 4 illustrates a second embodiment of a de-icing system 162including a non-rotating forward assembly 174 and a rotating rearassembly 176. A nosecone 164 is connected to an inlet guide vaneassembly 143. Generally, the inlet guide vane assembly 143 is connectedto a static structure of the aircraft and is configured to remainstationary about the longitudinal axis A. A fan hub 168 is configured torotate a fan 142. A second support member 186 is connected to the fanhub 168 and is configured to rotate about the longitudinal axis A.Accordingly, the forward assembly 174 is stationary and the rearassembly 176 rotates about the longitudinal axis A to generate an amountof windage.

Although the different embodiments have the specific components shown inthe illustrations, embodiments of this disclosure are not limited tothose particular combinations. It is possible to use some of thecomponents or features from one of the embodiments in combination withfeatures or components from another one of the embodiments.Additionally, the forward assembly, the rear assembly or both of theassemblies can rotate to generate heat.

The preceding description is exemplary rather than limiting in nature.Variations and modifications to the disclosed embodiments may becomeapparent to those skilled in the art that do not necessarily depart fromthe essence of this disclosure. The scope of legal protection given tothis disclosure can only be determined by studying the following claims.

What is claimed is:
 1. A de-icing system for a gas turbine enginecomprising: an exposed component defining an internal cavity, saidexposed component being one of a spinner and a nosecone that guidesairflow toward a fan; a forward assembly including a forward supportstructure that extends from an inner wall of said exposed component suchthat said forward assembly is at least partially located within saidinternal cavity at a location axially forward of said fan with respectto an engine longitudinal axis; a rear assembly adjacent to said forwardassembly; and wherein at least one of said forward assembly and saidrear assembly is moveable relative to the other of said forward assemblyand said rear assembly such that an amount of air friction is generatedin said internal cavity between said forward and rear assemblies at alocation defined by said exposed component.
 2. The de-icing system ofclaim 1, wherein at least one of said forward assembly and said rearassembly is rotatable relative to the other of said forward assembly andsaid rear assembly to generate said amount of air friction.
 3. Thede-icing system of claim 1, wherein said forward assembly and said rearassembly are axially spaced apart with respect to said enginelongitudinal axis to define a clearance gap, said clearance gap beingaxially forward of said fan with respect to said engine longitudinalaxis.
 4. The de-icing system of claim 1, wherein said forward assemblyand said rear assembly each includes at least one paddle.
 5. Thede-icing system of claim 4, wherein said at least one paddle includes aplurality of paddles, said plurality of paddles of said rear assemblyarranged to oppose rotation of said plurality of paddles of said forwardassembly in a circumferential direction with respect to said enginelongitudinal axis.
 6. The de-icing system of claim 5, wherein said rearassembly is at least partially located within said internal cavity. 7.The de-icing system of claim 6, wherein said rear assembly includes arear support structure extending from a fan hub, and said rear assemblyincludes a rotatable shaft that carries said plurality of paddles ofsaid rear assembly.
 8. The de-icing system of claim 6, comprising a sealconfigured to retain an amount of fluid within said internal cavity. 9.The de-icing system of claim 1, comprising an engagement mechanismconfigured to move said rear assembly in an axial direction with respectto said engine longitudinal axis between a de-icing position and aninoperable position.
 10. A gas turbine engine comprising: a fan mountedto a fan hub, said fan hub rotatable about an engine longitudinal axis;a compressor section, wherein said fan delivers airflow to an inlet ofsaid compressor section; a turbine section that drives said fan hub andsaid compressor section; an exposed component defining an internalcavity axially forward of said fan with respect to said enginelongitudinal axis, wherein said exposed component includes one of aspinner and a nosecone that guides airflow along a flow path toward saidfan; a de-icing system including a forward assembly and a rear assemblyeach located within said internal cavity such that said forward assemblyis at least partially located within said internal cavity at a locationaxially forward of said fan with respect to said engine longitudinalaxis, and such that said rear assembly and said internal cavity areaxially forward of said compressor section with respect to said enginelongitudinal axis; and wherein at least one of said forward assembly andsaid rear assembly is rotatable relative to the other of said forwardassembly and said rear assembly such that an amount of heat is generatedin said internal cavity between said forward and rear assemblies at alocation defined by said exposed component.
 11. The gas turbine engineof claim 10, wherein said forward assembly and said rear assembly areaxially spaced apart to define a clearance gap, said clearance gap beingaxially forward of said fan with respect to said engine longitudinalaxis.
 12. The gas turbine engine of claim 11, wherein said forwardassembly and said rear assembly each includes a plurality of paddles,said plurality of paddles of said rear assembly arranged to opposerotation of said plurality of paddles of said forward assembly in acircumferential direction with respect to said engine longitudinal axis.13. The gas turbine engine of claim 10, wherein said forward assemblyincludes a forward support structure extending in an axial directionfrom an inner wall of said exposed component that defines said internalcavity toward said fan hub with respect to said engine longitudinalaxis.
 14. The gas turbine engine of claim 13, wherein said fan hub ismounted to said spinner, and said exposed component is said spinner. 15.The gas turbine engine of claim 13, comprising an inlet guide vaneassembly mounted to said nosecone, and said exposed component is saidnosecone.
 16. The gas turbine engine of claim 13, wherein said rearassembly includes a rear support structure extending from said fan hub.17. The gas turbine engine of claim 13, wherein: said forward assemblyincludes a first set of paddles mounted to said forward supportstructure; and said rear assembly includes a second set of paddlesmounted to a rear support structure such that said first set of paddlesare axially spaced apart from said first set of paddles with respect tosaid engine longitudinal axis to define a clearance gap, said clearancegap being axially forward of said fan with respect to said enginelongitudinal axis.
 18. The gas turbine engine of claim 17, comprising:an engagement mechanism configured to move said second set of paddles ofsaid rear assembly in said axial direction between a de-icing positionand an inoperable position; and wherein a length of said clearance gapcorresponding to said de-icing position is less than a length of saidclearance gap corresponding to said inoperable position such that saidsecond set of paddles oppose rotation of said first set of paddles insaid de-icing position to cause said forward assembly and said rearassembly to mechanically generate the amount of heat in said internalcavity, but said second set of paddles do not oppose movement of saidfirst set of paddles in said inoperable position.
 19. The gas turbineengine of claim 17, wherein said first set of paddles and said secondset of paddles are positioned in a portion of said internal cavity thathas a generally dome-shaped configuration.
 20. The gas turbine engine ofclaim 10, comprising an engagement mechanism configured to move saidrear assembly in an axial direction with respect to the enginelongitudinal axis between a de-icing position and an inoperableposition.
 21. A method of de-icing a gas turbine engine, comprising:mechanically generating an amount of heat within an internal cavity ofan exposed component at a location that is axially forward of a fan withrespect to an engine longitudinal axis, including rotating at least oneof a forward assembly and a rear assembly relative to the other of saidforward assembly and said rear assembly to mechanically generate saidamount of heat; and transferring said amount of heat from said internalcavity to a surface of said exposed component adjacent to said location.22. The method as recited in claim 21, wherein the step of mechanicallygenerating said amount of heat includes generating an amount of airfriction within said internal cavity.
 23. The method as recited in claim22, wherein said forward assembly includes a first plurality of paddlesconnected to said exposed component, said rear assembly including asecond plurality of paddles connected to a rotatable shaft, said firstand second plurality of paddles each extending in a radial directionwith respect to said engine longitudinal axis, and said exposedcomponent including one of a spinner and a nosecone that guides airflowalong a flow path toward said fan.